The compressors and the turbines of an axial turbine engine each comprise a plurality of annular rows of blades. They enable an annular flow of air to be accelerated, slowed, rectified or even redirected. These functions enable the flow to be compressed or a drive energy to be recovered therefrom. In order to perform these roles in the aeronautical field, the blades have to be light in order to reduce the mass of the turbine engine. The weight reduction is also equivalent to a reduction of inertia in the context of a rotor.
The optimization of the mass of a blade nonetheless has to comply with criteria of mechanical strength and thermal resistance. A blade has to withstand vibrations; and where applicable occurrences of ingestion of foreign bodies. In addition, the rotor blades are subjected to centrifugal force. All these parameters complicate the design of the blades, all the more so since they vary in each aspect. In order to provide custom-made blades which comply with the demands set out above, it is known to design then produce blades with lattice.
Document US2013/0276461 A1 discloses a hollow axial turbine engine blade. The blade has an internal cell which is delimited by an external skin which has an intrados surface and an extrados surface. The cell is occupied by a three-dimensional lattice with nodes between the rods thereof. The lattice connects the intrados and the extrados. Furthermore, it is integral with the skin as a result of an additive production method. This method uses a powder as a filler metal that is deposited then solidified in layers.
Such a type of blade provides a large degree of freedom of design, which simultaneously enables the mechanical strength and the mass to be optimized, as a result of the presence and the absence of material at different locations. The additive production imposes the provision of an opening in the cell in order to empty it of non-solidified powder. During operation, the opening exposes the cell to the environment of the blade, which can damage it and make it heavier, so that an imbalance may appear on a rotor which is provided with such blades.